<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        class person{
            constructor(name,age){
                console.log("hello world")
                this.name=name;
                this.age=age;
            }
        }
        var li =new person("lisi",18)
    </script>
</body>
</html>